[EN] Error in PDF syntax

Description

“Error in PDF Syntax” is a general error that occurs when a PDF document contains syntactic problems. This means the PDF file does not fully comply with the PDF specifications and therefore cannot be correctly processed by PDF readers, parsers, or editors. Syntax errors in a PDF can have various causes and usually require careful examination of the PDF code.

Common Causes

• Missing or incorrect PDF object structures
  Each PDF object must be correctly structured (e.g., << ... >> for dictionaries, [] for arrays). Missing or malformed objects can trigger syntax errors.

• Incomplete or corrupted data
  Data that was truncated or corrupted during PDF creation or editing can cause syntax errors. Examples include incomplete streams or invalid object references.

• Incorrect object references
  An object may reference a non-existent or misplaced object, such as a dictionary pointing to a missing object.

• Invalid end markers (EOL)
  Missing or incorrect endobj or endstream markers can make the PDF invalid.

• Incorrect string or character usage
  Improperly escaped characters in text objects or strings (e.g., missing escape sequences for special characters) can break the PDF syntax.

• Invalid object IDs
  Each PDF object should have a unique ID. Duplicated or incorrect IDs can cause errors.

• Faulty header or incomplete file
  A PDF should begin with a proper header like %PDF-1.4. Errors in the header or missing initial data can lead to syntax issues.

Suggested Solutions

1. Check syntax with a Preflight tool

   • Use Adobe Acrobat Preflight or a similar tool to locate and identify errors.

2. Recreate the PDF if necessary

   • If the PDF is heavily corrupted or the syntax cannot be repaired, generate the PDF again from the original source (e.g., InDesign).

   • Ensure that PDF export settings are correctly configured and PDF/X-compliant if required.

Reference:

• x [EN] Overview – Syntax errors in the PDF page description